Tardis. Sexy, her last words in her mortal form were of River. ‘At the end, she kept talking…’ She kept repeating her words to make sure Rory remembered. ‘The only water in the forest is the river’, her last words through Idris before being released back into the TARDIS.
She knows who River is. As much as River is Amy and Rory’s daughter, she is also the child of the TARDIS.
(I like to ramble but feel free to delete the commentary if reblogging just for gifs)